1. Field of the Invention
This invention relates generally to an anchor system for glass railings, and more particularly, to a glass railing anchor system that uses two rows of adjustable anchor bolts along a glass railing anchor that are staggered along a two lines to distribute tensile and compressive loads on the anchor and anchor bolts allowing use of the glass railing anchor system in high velocity wind zones, such as high velocity hurricane zones (“HVHZ”).
2. Description of the Background Art
Conventional glass railing anchor systems known in the background art comprise surface or side mounted systems. With reference to FIGS. 1-4, a typical background glass railing anchor system 1 is shown and comprises a glass panel 2 supported in a bottom shoe base 3. The bottom shoe base 3 comprises a U-shaped base that is anchored to a concrete substrate by a plurality of threaded rods or expansion anchors 4 that are anchored along a straight line throughout the length of the base 3. A glass setting block 5 sits in the bottom of the channel formed by the U-shaped base 3 for receiving and supporting the glass panel 2. A typical glass railing comprises a plurality of glass panels separated by a one inch (1.0″) glass joint or post 9. The glass panel 2 is secured in the channel by a grouting or glazing agent 6 and, in some cases, further secured by a rubber gasket 7. Typical glass rail anchor systems known also include a top rail glass cap 8a or vinyl cap 8b. To improve the aesthetic appeal of the U-shaped base shoe 3, some systems decorate it with a cover.
There are many disadvantages with conventional glass railing anchor systems, such as surface and flush installation systems. A primary disadvantage with existing glass railing anchor systems is that they are not designed for high wind hurricane zones (HVHZ) or other areas susceptible to high winds. This is because they are not properly shimmed or reinforced and are susceptible to bending along the centerline, where half the anchor is in tension and the other half in compression. This weakness results because the anchors 4 used to secure the base 3 to the concrete substrate are installed along a center line making them subject to bending and stress along the center line.
Known systems are also unable to drain water off balconies and they make direct contact with concrete or are embedded in grout causing corrosion of the base and coating. In surface or side mounted installations, the base is typically aluminum and in direct contact with concrete causing corrosion of the aluminum and failure of coating. In flush mounted installations, the entire base is embedded in grout in order to minimize the appearance of the base. However, most grouts are highly alkaline causing corrosion of the aluminum and failure of coating. These known attachment methods also do not provide a permanent waterproof seal of the anchor base or drainage, which permits water intrusion directly into the center of the concrete defeating most waterproofing techniques and promoting corrosion. In addition, typical base dimensions provide insufficient use of materials, wherein the base is up to three times heavier than necessary and more difficult to install. Moreover, conventional U-shaped bases typically have tall profiles and square shoulders giving them an artificial appearance, making them more difficult to conceal and facilitating the potential retention of water.
Another issue with existing glass rail anchoring systems is that the expansion anchors or threaded rods used cannot be relocated to avoid interference with reinforcement steel in the concrete without drilling new holes at the site and affecting the integrity of the substrate. Holes drilled in the field compromise the integrity of the aluminum coating system due to the unfinished edge, which can cause warranties to be reduced in half because of the field modifications. The use of expansion anchors can also cause undesirable internal stress within the concrete, especially at the edge of the balcony and induce undesirable compressive loads. These internal stresses can cause the concrete to spall creating structural problems, raising life safety concerns and accelerating corrosion, along with other problems. Accordingly, typical anchor placement and size prohibit placement of the system close to the balcony edge, if it can be used at all.
Conventional glass railing anchor systems have several other disadvantages. Traditional post mounted glass railing systems utilize posts and top caps, which obstruct the view through the glass. Glass railing anchor systems currently known rely on shims for leveling and supporting the system as they are not adjustable. The use of shims for leveling is cumbersome and creates an unsightly joint that must be covered to conceal the shims and joint. Most base mounted systems also rely upon a rubber gasket material for the retention of glazing. As a result, glass bears upon the rubber rather than structural grout reducing its bearing capacity. In addition, larger base shoes must be used in conventional systems to support glass because of inherent bearing capacity deficiencies.
Given the foregoing shortcomings in conventional glass railing anchor systems, there exists a need for a glass railing anchor system that is stronger to withstand the stresses, strains and compression realized in HVHZ and other high wind conditions; waterproof; adapted for installation in concrete along the edges without inducing undesirable compression loads; adapted for providing drainage to alleviate or eliminate corrosion from water accumulation and contact with concrete; designed to require less material; lighter; more aesthetically pleasing; adjustable; designed to not require pre-drilling of the base or drilling on location; and less costly. As there are no known devices or systems that provide a glass railing anchor system that adequately or effectively address these issues, there exists a need for such a device and system. It is, therefore, to the effective resolution of the aforementioned problems and shortcomings of the prior art that the present invention is directed. The instant invention addresses this unfulfilled need in the prior art by providing a glass railing anchor system as contemplated by the instant invention disclosed herein.